JPH0665875B2 - Engine control device for air conditioner - Google Patents

Description

Description: [Industrial application] The present invention relates to a cooling device installed and set in, for example, an automobile, and particularly starts an auxiliary diesel engine for driving and controlling the cooling device. The present invention relates to a control device for controlling an engine for a cooling device.

[Background Art] In a vehicle-mounted cooling device, an auxiliary engine is provided for a main engine, and the cooling device is drive-controlled by the auxiliary engine. In this case, a diesel engine is used as the auxiliary engine, but when starting control of such a diesel engine, it is necessary to perform preheating control by a glow plug.

Here, in a running diesel engine mounted on a vehicle, particularly in a starting operation at a low temperature in a cold region, the starting operation was performed after the glow plug was sufficiently preheated, and the starting failed. Occasionally, it is necessary to re-heat before the starting operation.

On the other hand, in the case of the auxiliary diesel engine for the air conditioner, the low plug is used by operating the engine when the outside air temperature is high, and is not used in the low temperature state. Therefore, there is usually no start failure in this type of auxiliary engine. When the compressor of the cooling system is directly connected to such an auxiliary engine for cooling, the engine itself is turned on / off in conjunction with the turning on / off of this compressor. Therefore, the diesel engine used for cooling has a peculiar property that the start and stop operations are repeated, that is, the glow control relay is repeatedly turned on and off.

The current supplied to the glow plug that executes the preheating control of the diesel engine is about 20 to 30 A in a steady state, but the starting current thereof rises to about 100 A. Therefore, in order to drive and control the cooling device, when the main switch that controls the operation of the auxiliary engine is rapidly turned on and off, the relay circuit that controls the supply of the preheating current to the glow plug is provided. The contact opens and closes the large starting current, and the contact portion is welded.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and is particularly useful in a diesel engine used for cooling, where on / off operations may be frequently performed. The preheating current control for the glow plug that preheats the engine is not controlled to open / close at a high value such as the starting current value, but the switching control is executed only at the steady preheating current state to prevent unnecessary failures. It is an object of the present invention to provide a control device for an engine for a cooling device, which can effectively prevent the occurrence.

[Means for Solving the Problems] That is, in the engine control device for driving the cooling device according to the present invention, the preheating current is supplied to the glow plug from the time when the main switch for starting the cooling device is turned on. In addition to the supply setting, the starter command is given after a lapse of a specific time set by the timer device after the preheating current is set by the supply, and in the set time range of the timer device, the glow command is set. The interruption of the preheating current to the plug is prohibited, and the interruption control of the preheating current is executed only when the preheating current is in the steady state.

[Operation] In the engine control device configured as described above,
When the main switch is turned on, the preheating current is set and supplied to the glow plug that preheats the diesel engine, and at the same time, the timer device is also start-controlled. Then, a starter command is given to the engine when the set time of the timer device has passed, and within the set time range of the timer device, the preheating current for the glow plug is set to a state where it is not cut off. It Therefore, the interruption of the preheating current in the time range in which the starting current is set to be supplied to the glow plug is prohibited, and a large value of the starting current is interrupted by a relay circuit that controls the opening and closing of the preheating current. It is something that should not be done.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

a) Circuit configuration FIG. 1 shows a control circuit of an auxiliary diesel engine for driving and controlling an in-vehicle air conditioner, which mainly controls the operation of this engine with respect to a DC power source 11 including an on-vehicle battery. Switch 12 is set to connect. The main switch 12 is set to be turned on together with the operation command, and the operating power is supplied to the control relay 14 via the diode 13 in the turned-on state. At the same time, power is supplied to the operation stop relay 15.

The control relay 14 is a contact 14 that is normally set to open.
The contact 14a includes a glow control relay 16, a starter relay 17, a control auxiliary relay 18, an abnormality detection relay 19, and a first timer circuit 20 by closing the contact 14a in an operating state.
To set the power supply circuit for. The timer circuit 20 is controlled to start when the contact 14a is closed and the power supply is set, and the contact 20a is closed when the time range required for preheating (for example, about 5 seconds) has elapsed. It comes to switch control.

This switching contact 20a sets the power supply to the control relay 14 via the diode 21 in the closed state of the contact 14a, and is switched and driven when the set time of the timer circuit 20 has elapsed, The power supply circuit for the control relay 14 is set via the contact 18b (normally closed) of the auxiliary control relay 18 and the diode 22.

Further, when the contact 20a of the timer circuit 20 is switched, power is set to be supplied to the starter auxiliary relay 23 and the second timer circuit 24.
The normally open contact 23 a of 23 is connected in series to the power supply circuit of the starter relay 17.

In addition, this starter relay 17 and glow control relay
In the 16 circuits, the contact 24b of the second timer circuit 24 and the engine speed detection contact 25 are connected and connected in series. Here, the contact 24b is opened when a predetermined time elapses after the power supply to the timer circuit 24 is set, and the contact 25 is the rotation speed of the engine corresponding to the operating state of the engine. It will be opened when it rises to.

Further, the power supply circuit of the abnormality detection relay 19 is configured such that power is supplied and set in parallel through sensor contacts 26 and 27 that detect, for example, cooling water temperature of the auxiliary engine, abnormal pressure in the cooling cycle, etc. ing.

For the contact 14a of the control relay 14, the normally closed contact 15b of the operation stop relay 15 and the normally open contact 1 of the abnormality detection relay 19
9a is further set in parallel, and power is supplied to the stop control solenoid 28 via these contact circuits. That is, power is supplied to the solenoid 28 in the return state of the operation stop relay 15 or the operation state of the abnormality detection relay 19, and a stop command is issued to the engine that drives the cooling device to control the stop of the engine. It is a thing.

In addition, a glow plug that performs the preheating operation of the engine
The reference numeral 29 controls the supply of power via the normally open contact 16a of the glow control relay 16, and the preheating operation is executed in the operating state of the relay 16. The starter 30 is connected and set to the power supply 11, and the starter operation command is supplied and set to the starter 30 via the contact 17a of the starter relay 17. That is, the starter motor is rotationally driven in the operating state of the starter relay 17,
Engine start control is executed.

b) Operation of the control circuit That is, in the control circuit of the cooling device driving disel engine configured as described above, when the main switch 12 is turned on and set to set the cooling operation state, the operation is performed via the diode 13. Control relay 14 is set to operate and its contact 14
a closes. When the contact 14a is closed, the contact 24b and the contact 25 for detecting the engine rotation are closed, so that an exciting current is supplied to the glow control relay 16 and the relay 16 operates to close the contact 16a. Then, the preheating current is supplied to the glow plug 29, and the preheating state of the engine is set.

Further, by closing the contact 14a, power is set to be supplied to the first timer circuit 20, and the time counting operation is started. At this time, the drive current is also supplied to the control auxiliary relay 18, and its contact 18b is also set to the open state. Further, the operation stop relay 15 is set to the operation state in response to turning on of the main switch 12. Then, the contact 15b is opened to set the state in which the operation of the stop solenoid 28 is prohibited.

In this way, the preheat state is set according to the operation of the main switch 12, but the timer circuit
When the time set by 20, for example, 5 seconds elapses, the contact
20a is switched so that power is supplied to the starter auxiliary relay 23 and the second timer circuit 24. Then, the contact 23a is closed by the operation of the relay 23, and the starter relay 17 is set to operate, and the contact 17a is closed by the operation of the relay 17 so that a start command is given to the starter 30. become. That is, the starter motor is driven and the diesel engine that is preheated is started and controlled.
Further, the second timer circuit 24 starts to count the time with this starter command.

In such a starter command state, if the engine speed does not rise within the set time range of the second timer circuit 24 (for example, about 5 seconds), the contact 24b of the second timer circuit 24 opens. The power supply circuits of the glow control relay 16 and the starter relay 17 are cut off to stop the preheating and the cranking operation of the engine.

If the engine speed rises within the set time range of the second timer circuit 24, the rotation speed detection contact 25 opens.
Preheating and starter clamping are completed in the same manner as above, and the rotational operating state of this engine is set. Then, the cooling operation is started by this engine.

When the cooling operation is being executed by the auxiliary diesel engine as described above, when the cooling operation is to be ended, the main switch 12 may be controlled to open. That is,
When the switch 12 is opened, the power supply to the operation stop relay 15 is cut off and the contact 15b is closed. In this case, the control relay 14 has its own contact 14a, the first
The self-holding setting is made via the contact 20a set by switching of the timer circuit 20 and the contact 18b of the control auxiliary relay 18 restored by the opening of the contact 25, and therefore is stopped by the closing operation of the contact 15b. A current is set to be supplied to the solenoid 28, and the engine stop operation is executed.

In this way, when the engine speed becomes low and the engine stops, the engine speed detection contact 25 is closed and current is supplied to the auxiliary control relay 18 to open the contact 18b.
The power supply circuit for 4 is turned off and the state shown in the figure is restored and all circuits are set to stop.

Further, in such a circuit device, assuming that the main switch 12 is turned on in the stopped state as shown in the figure and preheated, for example, the main switch 12 is operated to open the circuit as follows. become.

That is, when the main switch 12 is turned on and set, the control relay 14 is set to the operating state and the preheating current is set and supplied to the glow plug 29 as described above. The timer circuit 20 is also set to operate.

When the main switch 12 is operated to open in the preheated state, the operation stop relay 15 returns and the operation of the engine is prohibited.
The control relay 14 is set in the operating state by self-holding via the contact 14a and the contact 20a. Therefore, glow plug
The supply of preheat current to 29 will continue regardless of the opening of the main switch 12. The supply of the preheating current to the glow plug 29 is continued until the contact time 20a is switched and driven after the set time of the first timer circuit 20 has elapsed.
The control relay 14 is reset in response to the lapse of the set time of 20. That is, the control circuit returns to the stopped state,
The operation of the next main switch 12 is waited.

That is, when the preheating current is supplied to the glow plug 29, the preheating of the glow plug 29 is continued until the time (for example, about 5 seconds) set by the first timer circuit 20 elapses. The current cutoff is prohibited. Therefore, the state in which the starting current for the glow plug 29 is cut off does not occur, and the occurrence of troubles such as welding of the contacts for controlling the opening / closing of the preheating current is effectively prevented.

Further, in the case where a failure occurs in the engine temperature, the pressure of the cooling cycle, or the like in the operating state of the cooling device, one of the sensor contacts 26 and 27 is closed and the abnormality detection relay 19 is set to operate. . When this relay 19 is operated, its contact 19a is closed, power is supplied to the stop solenoid 28, and the engine is stopped and controlled.

Second Embodiment In the above embodiment, the first timer circuit 20 that sets the preheating time range for the glow plug prohibits the cutoff of the preheating current within the set time range of the timer circuit 20. I have to.

However, as shown in FIG. 2, a special third timer circuit 31 for preventing interruption of the starting current to the glow plug 29 may be provided. That is, the third timer circuit 31 is configured such that the operating power source is set in the operating state of the control relay 14, and the normally closed contact 31b is the contact 1
Control relay connected via diode 21 in series with 4a
It is set to supply operating current to 14.
In this case, the contact 20a of the first timer circuit 20 is a normally open contact that controls the opening and closing of the circuit for the diode 22. In addition, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

That is, in this circuit, when the main switch 12 is turned on and the control relay 14 is set to operate and the preheating current is supplied to the glow plug 29, the preheating time is set to the first timer. Third timer circuit with circuit 20
31 starts to count. And the third timer circuit
The power supply circuit for the control relay 14 is set through the contact 31b until the set time of 31 elapses, that is, the time range in which the starting current of the glow plug 29 exists.

Therefore, for example, even when the main switch 12 is turned on and the circuit is operated immediately thereafter, the control relay 14 is kept in the operating state until the set time of the third timer circuit 31 elapses, The interruption of the preheating current to the glow plug 29 is prohibited. That is, the interruption of the preheating current in the state where the starting current exists for the glow plug 29 is prevented.

In the above embodiments, the state of the logic circuit configured by a general timer circuit or relay is shown.
The present invention is not limited to the above logical configuration, but can be similarly configured by an electronic circuit using a transistor or the like, and can also be configured by a microcomputer.

[Effects of the Invention] As described above, according to the present invention, for example, in a cooling device mounted on an automobile or the like, when the cooling control of the cooling device is performed by a diesel engine that is specially set, the cooling device is cooled. The start / stop control of the engine is executed by turning on / off the switch for controlling the operation of the apparatus. When the engine start / stop control is performed by this switch, the control of the preheating current for the glow plug for preheating the engine becomes a state in which the off control in the state where the starting current exists is prohibited. Thus, it becomes possible to reliably prevent and control the occurrence of a failure due to a large starting current in the preheating current switching circuit. Therefore, the operational safety of the operator can be effectively ensured particularly when the cooling device is set for a vehicle.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram illustrating a control device for an engine for a cooling device according to an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram illustrating another embodiment of the present invention. 11 …… DC power supply (vehicle battery), 12 …… Main switch,
14 …… Control relay, 15 …… Operation stop relay, 16 …… Glow control relay, 17 …… Starter relay, 18 …… Control auxiliary relay, 20, 24,31 …… Timer circuit, 28 …… Stop solenoid, 29 …… Glow plug, 30 …… Starter.

Claims (1)

[Claims] 1. A glow plug for preheating a diesel engine for driving an air conditioner, a control relay operated in response to turning on of a main switch, and a preheating current supplied to the glow plug according to the operation of the control relay. The glow control relay, and a timer device that measures the passage of a specified time range from the time of turning on the main switch with the operation of the glow control relay, and the passage of the specified time with this timer device was confirmed. A means for later giving a starter command to the engine, and a preheating current supply to the glow plug while maintaining the operating state of the glow control relay until the elapse of another specified time is confirmed by the timer device. And keeps the glow control relay in an operating state without involving the return of the main switch. A means for prohibiting the interruption of the preheating current to the engine, a means for detecting the increase in the engine speed and returning the glow control relay, and cutting off the starter command, and the other means set by the timer device. A control device for an engine for a cooling device, wherein a preheating current to the glow plug and a cutoff of the preheating current are not repeatedly executed within a set time range.